Well-drilling apparatus



S. J. MATHEWS.

WELL DRILLING APPARATUS.

APPLICATION FILED JULY 19, 1920.

1,43 3%, Patented Nov. 28, 1922.

INVENTOR S.J.MATHEWS Bvggw ATTORNEY Patented ov. 28, 192.

SAMUEL J. MATHEWS. OF SAPULPA, OKLAHOMA, ASSIGNOR TO B.-B. MANUFACTURING AND DIHLLING COMPANY, A CORPORATION OF DELAWARE.

WELL-DRILLING APPARATUS.

Application filed July 19, 1920. Serial N0. 397,217.

T all whom it may concern:

Be it known that I, SAMUEL J. MATHEWS, a citizen of the United States of America, residing at the city of Sapulpa, State of Oklahome, United States of America, have invented a certain new and useful Well-Drilling Apparatus, of which the following is such a full, clear and exact description as will enable anyone skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification.

My invention relates to well drilling aparatus, particularly of the class shown and esci'ibed in Patent No. 1,077,620 granted to me November 4., 1913, and its principal object is to provide an. improved drill bit ca able of operating efiiciently under direct,

drive by a high speed motor. Other objects and advanta s of my invention will appear from the 0 lowing more detailed descrip tion.

In the accompanying drawing which illustrates one form of device in accordance with my" invention, Fig. 1 is a view showing the device in position in a well. Fig. 2 is an enlarged side'view of the bit. Fig. 3 is a view of the bit taken at right angles to Fig.

2, and Fig. 4 is a bottom plan view of the bit.

5 indicates a well casin in which the motor casin 6 is Suspender? by means of a, rope or cab e 7. The motor casing 6 con- 85 talns any suitable form of high speed motor,

such for instance, as shown prior patent above referred to. The motor in the casing 6 drive a tool shaft 8, the lower end of which is secured to a boring head 9. The boring head 9 is provided with two airs of abrasive bits '10 and 11 respective y. These bits are formed of suitable abrasive material, preferably carborundum. The bits 10 are of such d1- ameter as to pass down through the well casing 5 and are rigidly carried by the boring head 9. Thebits 11 are adapted to project beyond the well casing 5 so as to produce an enlarged passage through which the casing can be lowered as shown in Fig. 1. These bits 11 are pivoted to the boring head 9 at 12 so that they will assume a vertical position to permit the boring head to pass through the 'well casing when not 56 rotating, and are brought to their horizonsive bit driven at relatilve y hli h speed there- 'by, said bit being provided wit a recess at its in my tal operating osition by the centrifugal force develope by the high speed of rotation of the tool- 13 is a stem projecting downwardly from the boring head 9 and carryin a pilot bit.14 which is also formed of car orunduin or other similar material. The pilot bit 14 is made substantially semi-circular in cross section and it is provided at its central point with a recess 15 adaptedv to form a slender centering cone WhlCh may be broken or crushed by the weight of the descendin tool.

As the pilot bit is positioned a substantial distance below the main bit a water reservoir is formed at the bottom of the well which will contain suflicient water to labricate both the pilot and main bit. The high speed of the bit, which may be from 1000 to 2000 revolutions per minute, permits the extension members of the bit to be thrown into their working position by centrifugal. force alone. This enables me to produce an expansion bit without the use of springs and one which consequentlymay be passed through the well casing without" any liability of becoming caught therein.

I claim:

1. In a device of the class described, the combination with drivin means, of an abraneutral point for forming a frangible centerin cone.

2. n a device of the class described, the combination with drivin means, of a main bit .of abrasive materia, and a pilot bit also of abrasive material, said pilot bit being of less diameter than said main bit and positioned a substantial distance below the same.

3. In a device of the class described, the combination with driving means, of a plurality of abrasive bits positioned at different levels, one of said bits being rovided with a recess at its neutral point or forming a 100 frangible centering cone.

4. In a device of the class described, the combination with driving means, of a bit of abrasive material, said bit bein substantially semicircular cross section and provided 105 at its neutral point with a recess for forming a frangible centering cone.

.5. In a device of the class described, the combination with a main abrasive bit having a flat 'underface, of a. pilot bit also of abrano main bit, said pilot bit being rovided at its neutral point with a recess or forming a frangible centering cone.

In testimony whereof, I have hereunto set my hand and affixed my seal.

SAMUEL J. MATHEWS. 

